


The Truth in the Charm

by cathcer1984



Category: Harry Potter - J. K. Rowling
Genre: Age Difference, Age Regression/De-Aging, Bottom Harry Potter, Bottoming from the Top, Consensual Underage Sex, De-Aged Severus Snape, M/M, Older Harry, Older Harry Potter, Professor Harry Potter, Underage Sex, time travel (sort of)
Language: English
Status: Completed
Published: 2018-01-22
Updated: 2018-01-22
Packaged: 2019-03-08 02:13:26
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,400
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13448364
Author URL: https://archiveofourown.org/users/cathcer1984/pseuds/cathcer1984
Summary: The Patronus Charm is susceptible to the casters magic and emotions, it can reveal things that the caster refuses to accept.





	The Truth in the Charm

**Author's Note:**

> I had a great time with this prompt, I love age difference and younger!Severus is always a great take on the old trope!
> 
> A giant thank you to my beta icicle33
> 
> Snarry Glompfest for corona_0304

The Great Hall hadn’t changed much since his time as a student, but even so Harry didn’t feel like eating dinner just yet and decided to take a stroll around the grounds. As he passed students coming in from Herbology and Care of Magical Creatures, he nodded and, greeted them as they said, “Hello, Professor Potter” or “Good evening. Professor”.

Harry loved Hogwarts in the autumn— the red and gold and brown leaves floating around on the wind made everything seem that much more special. As he made his way down towards the forest, he was surprised to see a lone figure standing by an unnaturally still Whomping Willow. Changing his path, Harry made his way towards the student.

When he was close enough, Harry said, “You should be inside having dinner.”

“I should but I don’t like to. I don’t like the Great Hall it reminds me of bad things. Things that I don’t remember.”

“I know it’s difficult for you, Severus, but you need to learn how to live as a teenager again.”

“Again, that’s the terrible part. I’ve been through this once before.” Severus Snape, seventeen and sullen, hunched his shoulders and turned his back on Harry.

It had been a surprise for everyone when five years after the Battle at Hogwarts the Whomping Willow had stopped moving and out from underneath its roots came a younger, sixteen year old Severus Snape with no idea of anything other than his last memory of being lured under the tree by Sirius Black.

It had taken extensive testing by Minerva, Harry, and Poppy to determine that in the past five years Severus’ body had healed itself and retreated to a state his magic had deemed safe, the age of sixteen. That had been a year ago, and sometimes, Severus suffered from bouts of deja-vu when he’d do something he’d done before, or most commonly in Harry’s classes, when he got told of the Wars and, inadvertently, his role in them.

Due to this, he spent more time in the library than was healthy, trying to find out everything about the two wars, and when neither Minerva, nor Madam Pince got through to him Harry decided to give it a go. He was snapped at as soon as he came within sight of the table Severus had ensconced himself.

Harry had simply replied, “Instead of reading inaccurate books with only half the information, why don’t you ask someone who was involved with the war and with your- your adult self’s role?”

It had taken three weeks before Severus h approached him after class to explain what had happened and why. They had to take it slowly so Harry didn’t overwhelm him with emotion and Severus’ magic wouldn’t then lash out. He’d been nearly inconsolable when he realised that Lily Evans was dead and that he was a part of the reason.

Now, he was seventeen again and in his final year of Hogwarts, again, but now he had a future. He could do whatever he wanted to do and Harry found himself feeling despondent at the thought of not seeing Severus again. Harry had grown to like Severus; the teen was intelligent and sarcastic, and for Harry, it was easy to differentiate between him and Snape, the bitter and hated Potions Professor.

“Being seventeen isn’t that bad, Severus. Besides, you have your future ahead of you, something that you didn’t before. From the moment you leave Hogwarts you will be a different man to him.” Harry didn’t need to clarify who. “From now you will never be what he was, you will be someone else, someone different.”

“Someone good you mean.”

“You are good. He was good. He was one of the best men I knew, one of the bravest. You are still that man, Severus,” Harry said, laying a hand on the young man’s shoulder. “You just don’t have to make the choices he did. You get to start again; you get to be whoever you want.”

Severus’ dark eyes bore into Harry before he was suddenly moving, pressing his mouth to Harry’s, clumsily kissing him. Harry allowed it for a minute before pushing him away. “Severus, I can’t. You are my student.”

“I’m of age.”

“Yes. Yes, you are.” Harry stroked a finger down the pale cheek. “But I’m still in a position of authority. When you leave here, maybe we can talk about going out or something, but right now... Right now, you need to go inside and calm down.”

With a soft growl, Severus stalked away from Harry who watched him go. As soon as he was out of sight Harry thumped his head against the Whomping Willow’s trunk. The rest of the year was going to be impossible with Severus hating him.

V*V*V*V

 

When classes started again on Monday, Harry couldn’t have been more wrong. Severus didn’t act as though he were angry with Harry; in fact, he seemed to be going out of his way to drive Harry to distraction.

His school robes were left undone and his white shirt was let tantalisingly unbuttoned near his throat. His hair looked soft and was pulled back into a small ponytail and his eyes never left Harry. Severus took notes but seemed to spend most of his time staring at Harry and sucking on the end of his quill.

It drew Harry in and he found it hard to take his eyes off Severus and continue to teach the class. At the end of the lesson, Severus sauntered up to his desk and said, “Professor Potter,” his voice was just as deep as it had been when he was an adult but not as smooth, though it was only a matter of time. He still spoke slowly, lingering and tasting each word before deliberately letting it fall into the space between them, “I was wondering if you could explain the concept behind the Patronus charm a bit more. I find myself curious as to how it is possible, and you appear to be the resident expert. I would like to learn it myself.”

Harry was eager to help but reluctant to be alone with Severus, though his curiosity as to what form Severus’ Patronus would take now made his mouth override his brain. He heard his voice saying, “Of course, I’ll teach you.”  
Seeing Severus smirk triumphantly, he hastily added. “Perhaps some of your classmates would like to join in? I’ll mention it next class.”

Severus’ face fell and he narrowed his eyes at Harry, knowing exactly what he was doing and why. but it didn’t stop that victorious sensation that flooded his gut. The game was on, and Harry knew that Severus would be doing everything in his power to get Harry alone. Harry needed to keep that from happening. Otherwise, he’d lose control and slam Severus into the nearest surface and …

Shaking his head, Harry stopped that thought. He couldn’t. Severus was his student. He hadn’t told anyone of their kiss, but he hadn’t stopped thinking about it. He was thirty years old and he was fantasizing about a man who had once been horrible to him, but was now, a teenager, an intelligent, witty teenager that, inexplicably, Harry wanted.

True to his word, the next Defence Against the Dark Arts class, Harry offered extra lessons for those that wanted to learn how to produce a Patronus. Naturally, the majority signed up and Harry caught Severus’ eye barely suppressing a grin at the calculating look in those dark eyes.

A few months later, on Hallowe’en and the game between Harry and Severus had gotten dangerous. They’d exchanged a few kisses that Severus initiated and Harry panicked when they heard footsteps. Mrs Norris caught them once, Filch not far behind her, and Harry was forced to explain he’d given Severus a detention. And then he was forced to spend an hour alone with Severus as he did everything in his power to seduce Harry.

Harry’s duty on Hallowe’en was easy as he cheated and used the Marauder’s Map to find where students were out of bed. Surprisingly, he caught sight of a name that he hadn’t expected to see, in a place he didn’t think they would be.

Climbing the stairs of the Astronomy Tower always brought Harry a sense of dread. He hated it; however, he was a teacher and had a responsibility to make sure no student was out of bed.

The door creaked as he pushed it open, but the student didn’t turn around. “I find it peaceful up here,” Severus said. “I don’t know why. I know that I shouldn’t but-”

“But?”

“But my magic likes it up here.” Severus finally turned to look at him, but his face was barely visible in the night time.

Harry licked his lips before he spoke. “I think it might be because this is the place where you fulfilled one life debt and a vast component of a second one. More than likely your magic remembers, even if your mind does not.”

“Do you want to know something else my magic remembers?”

Moving so he stood shoulder to shoulder with Severus, as they leant against the balustrade looking down onto the Hogwarts grounds, Harry nodded not trusting his voice after Severus’ tone had turned husky.

“You.”

Surprised, Harry turned his head, staring at the man beside him. “What?”

“My magic remembers you. I feel... calmer near you. Well, calm is a relative term, I suppose.” Severus’ lips quirked. “My magic feels calm. I feel randy and want to fuck you against the nearest surface.”

“You shouldn’t say that to me, Severus,” Harry whispered, though he made no move to stop Severus as he moved to press against Harry’s back, his cock grinding into the slight gap his trousers allowed between his arse cheeks.

“Because you’re my teacher.”

“That.” Harry huffed a laugh. “And I’m thirty-one years old. You’re seventeen Sev- Sev’rus.” Harry moaned as Severus’ hips had started to move and he rocked against Harry, one hand sliding around to cup at Harry’s half-hard cock. With a strength that his slim, wiry frame belied, Severus spun Harry round and he sunk to his knees, mouth on Harry’s cock, the heat and wetness seeping through his trousers and underwear.

Deft fingers undid Harry’s button and zip and drew his cock out into the cold air, which made him shudder for a brief moment before Severus’ mouth smothered him in a wet heat. He thrust slightly as Severus’ tongue swirled and his long fingered hand cupped Harry’s balls, rolling them in his palm before he swallowed around Harry’s cock.

The fingers moved and they pressed against the skin behind his balls and slid up to rub against his entrance. Harry let out an embarrassingly loud whine and didn’t know whether to push further down Severus’ throat or onto his fingers and forced them into himself.

It didn’t take long for Severus to allow both; he relaxed his throat and pressed a long finger into Harry, curling it just so and pressing against his prostate, swallowing around the head of Harry’s cock., pulling back until just the tip was in his mouth, as he pushed another dry finger against Harry’s rim where it was stretched around Severus’ index finger.

Harry came with a whimper, pumping his hips into Severus’ mouth as he swallowed everything Harry offered and kept sucking until Harry pulled him off with a murmur of “Too much.”

Standing, Severus looked debauched and Harry lunged, kissing him forcefully and pressing a hand to Severus’ cock. He’d barely grasped it when the younger man came, muscles clenching then relaxing as Severus went limp onto Harry’s chest.

“Fuck.”

“That comes later. Give me a few minutes though.” Severus chuckled.

“This isn’t funny, Severus. I could lose my job!” Harry pulled away and tried not to feel cold at the loss. He shoved his limp cock back into his trousers and did them up haphazardly. “This is the last time. This cannot, will not, happen again! I refuse to play this game anymore, Severus. This is stops now. No more!”

Storming away angrily, Harry left Severus standing alone on the Astronomy Tower and he couldn’t bring himself to regret leaving. Not when his fear at being jobless and homeless was so overwhelming.

V*V*V*V

 

The time between Hallowe’en and Christmas was a difficult one for Harry. Severus had completely backed off after Harry’s angry outburst and he had started to hang around with some Ravenclaws and Slytherins, especially one boy, Mark Johnson, a half-blood Ravenclaw with a passion for Potions that matched Severus’. They often paired up together in Harry’s class and in the extra Patronus lessons as well.

Severus’ Patronus was almost taking on a corporeal form and Harry estimated that it would be another class or two before it did. Mark, however, was no closer to producing anything more than a wisp of silver vapour from his wand, but he was at about the same stage as the rest of the class.

The next time they had a Patronus lesson would be the last time before the Christmas holidays and Harry knew that Severus wanted to find out the form of his before then. It was past the end of the hour session and Harry called out, “Okay everyone, time’s up. Have a good holiday and I expect to see some progress when you get back.”

The students filed out one by one, all of them wishing Harry a happy Christmas and New Year’s. It wasn’t until the room had emptied that Harry realised he wasn’t alone. Severus was still in the room, hair was falling from its binding, shorter stands framing his face and his eyes were narrowed in concentration.

When his face was red from straining, Harry made his way over and put his hands on Severus’ shoulders. “Relax. Calm down and just breathe.” When he felt Severus do just that, Harry said, “Close your eyes. Think of a happy memory and let it fill you up. Hold onto that feeling of elation. No, don’t tense, just relax.

“Now, breathe in and out and cast the spell,” Harry whispered, watching Severus’ wand as he shouted out, “Expecto Patronum!”

“Good, Severus, now open your eyes.”

Severus stood, staring at his corporeal Patronus; the same silver doe that had led Harry out to the Sword of Gyffindor stood before her master and she pranced around the two of them before galloping around the room and disappearing out of sight.

“Expecto Patronum,” Severus cried and the doe formed again. “Show me yours,” he demanded, and Harry knew that he shouldn’t. Severus would know what it meant, but Harry drew his wand and cast the spell anyway.

The stag and the doe danced around their masters before frolicking around each other and disappearing together out the window, their glow leaving a warmth to the room that hadn’t been there before.

Squaring his shoulders, Harry prepared to tell Severus no, against every fibre in his being, but the other man was looking at the window where the Patronuses had disappeared with a mild furrow to his forehead. He nodded once and picked up his bag, turning to leave the room. “Severus,” Harry called. He started to speak and changed his mind, instead saying, “Happy Christmas.”

“And to you, Professor.” Severus was long gone before Harry realised he’d been treated with the proper respect he deserved for the first time since Severus had become his friend. Deciding that he needed to think, Harry went for a walk around the castle. He avoided the Astronomy Tower and wandered the halls with a freedom that he never had in his youth.

He didn’t have to hide from Filch or Mrs Norris or any of the teachers, and Harry loved roaming Hogwarts at night. Still, he was slightly cold and was heading towards the kitchens for a cup of tea before bed when he heard a whimper.

Drawing his wand, Harry tiptoed around to where the sound had come from, an alcove in the Entrance Hall that was unnoticeable in the daylight and impossible to see in the dark. “Lumos,” he muttered; his wand light highlighted two students tangled together.

It wasn’t the first time students had tried to get the better of a teacher by making out or more in the alcove, but it was the first time Harry had been speechless.

“Johnson, Snape, get back to your dormitories. Now.” He growled when neither Mark nor Severus moved. In that moment Harry hated his student. It was not Mark’s fault, but Harry couldn’t stand to see Severus touching him. “Detention for both of you when you get back from the break.”

“Yes, sir,” Mark said, before rushing off without a backwards glance at Severus. When his footsteps had receded, it was just Harry and Severus alone, bathed in Harry’s wand light.

“How does it feel?”

“Excuse me?”

“To see me with someone else.” Severus sauntered up to Harry and said, “Are you jealous?”

“Of your teenage fumblings? I hardly think so.” Harry scoffed.

“Our Patronuses match.” Severus’ voice took on a whiny tone and he sounded petulant and immature. Harry felt tired; he just wanted to go to bed.  
He said, cruelly, “I like men, Severus. Not teenagers. Now get back to your dorm.” He walked away; this time he left Severus standing in the dark and not on a balcony, but he was just as alone as the last time he had walked away.

V*V*V*V

 

The Christmas holidays went slowly for Harry. He saw Severus everywhere, but he was never approached and nothing was said between them. It made Harry feel ridiculously sad; he missed Severus as his friend and he’d rather have that and deal with his attraction to the man then not have him at all.

By the time the students returned, Harry was sure he was crazy with want and need and desire for Severus. The first Patronus lesson after the break was an interesting one. Severus was the only student who could perform the charm and the others had made little progress, so Harry decided they’d learn some theory about the magic behind it.

“It’s susceptible,” he said, “to your emotions and your magic. I had a friend and her Patronus changed when she fell in love. It became a werewolf. The man she loved, he was a werewolf. Her Patronus reflected that and it changed. Yours may not be constant. What it is now doesn’t mean it’s going to stay that way.”

Severus’ eyes were wide with horror and it made Harry pause. Severus hadn’t realised what it meant for his Patronus to match Harry’s, Harry assumed he was going to be more determined than ever to be with Harry. Feeling out of sorts, he dismissed the students rather soon after that and escaped to his office.

Harry spent the next two weeks in a tense state. He kept waiting to be cornered by Severus, but it never happened. The thing was, Severus barely glanced at him anymore and Harry was the one caught staring. He’d watch Severus during mealtimes and be nudged by Neville when it was becoming too obvious. In class, Harry had to keep forcing his eyes away from the dark figure that was Severus as he shrunk in on himself, trying to look as inconspicuous as possible.

The new behaviour was not out of sorts for Severus, but it was a stark contrast to the past few months when he had been oozing confidence and sensuality. Soon enough, NEWTs were upon the Seventh Years and OWLs for the Fifth Years, and Harry had to push Severus to the back of his mind as he answered questions from panicked students.

Friday afternoon was the last exam and it was the Defence of the Dark Arts practical. Harry had a stern warning from McGonagall to stay in his office and not pester the students about how the exam went.

It was nearing six in the evening when there was a soft knock on the office door and it opened admitting Severus. He looked paler than usual, stressed by the exams, but he had squared his shoulders and kept his head high and eyes to the left of Harry’s head.

“Severus-”

“I’m officially not your student anymore. I’ve done my exam and there’s nothing more you can teach me. I’ve given you space. I’ve stayed away and now I’ve come to you. I’ve come to tell you -” Severus paused and took a deep breath. “I’ve come to tell you that I- I-”

“I know, Severus.”

“I’ve been planning that for weeks.” Severus’ shoulders slumped and he glanced at Harry for the first time.

Standing, Harry made his way to Severus. It seemed awkward. They had both put off this moment, and the way Severus expected rejection made it all the more awkward. “Severus, I have been rude and cruel to you. I know that. But know this. I don’t share. If you want this, truly want it, then I am yours. And you are mine.”

Stepping closer, Severus pressed his body against Harry’s. They were practically the same height and his lips brushed Harry’s as he spoke. “I’m a possessive man, Harry. I don’t give up easily, and you should know how much I want this by my Patronus.”

That was all Harry needed and he claimed Severus’ lips in a fierce kiss that was more tongue and teeth than anything else. But it was enough for the moment. Severus’ hands reached up and clutched at Harry’s shoulders, nails digging into the skin of his neck and Harry let out a moan. He moved his mouth to press kisses along Severus’ jaw, swiping his tongue to feel the scratch of his light stubble and down his neck.

Harry directed them around his desk. They bumped into it a few times before Harry was able to push Severus in the chair. Immediately he sank to his feet between Severus’ knees, desperate to taste his cock and repay the favour Severus had given him, on the Astronomy Tower, too long ago.

After he had released Severus’ cock from the confines of his trousers, Harry swirled his tongue around the head, relishing in the bitter, salty taste of Severus’ pre-come. Swallowing him down, Harry sucked hard and fumbled one handed with his own trousers. He was able to move his head to draw one of Severus’ balls into his mouth at the same time that he shoved his trousers down to his knees.

Moving back up to swallow Severus’ cock down, Harry coaxed Severus to orgasm with his hands and mouth and when Severus came down his throat he let out a loud shout before slumping back into the chair.

Harry stood and kicked off his trousers and straddled Severus’ thighs. He took his young lover’s chin in his hand and kissed him thoroughly, while he wandlessly summoned the lube from his adjoining bedroom.

He fumbled over their laps to slick his fingers, and he reached around to begin stretching himself. The angle made his wrist ache and Harry broke the kiss to rise up onto his knees, bringing his cock level with Severus’ mouth. Severus reached forwards, mouth open, but Harry grabbed his hair and kept him away. “You do that,” he panted “and I’ll come before you’re inside of me.”

“Nggh.” Severus groaned but Harry was finished stretching himself, and he withdrew his fingers and slicked Severus’ cock. Keeping a firm grip on it as he sank down, Harry closed his eyes and let himself just feel.

He felt the scratch of Severus’ trousers against his thighs, the biting of the zip against his arse cheeks, the stretch of Severus’ cock as it filled him.  
The heat of Severus’ breath as he panted hotly, the feel of his hair in Harry’s hand and the grip of his hands on Harry’s hips in a bruising grip.

“Please. Harry, please move,” Severus begged, his cheeks red, and Harry moved his hands from Severus’ hair to the back of the chair as leverage as he began to move. The burn was pleasurable as Harry moved up and down Severus’ cock. He clenched on the way up not really wanting Severus’ cock to leave his body at all.

It came as a pleasant surprise when Severus’ long fingers wrapped around his cock and tugged harshly. There was something illicit about having sex in his office, half-dressed, but it drove Harry closer to the edge. When Severus’ came inside of him, the feel of his come filling Harry up and the way Severus’ hand tightened about his cock, flung Harry over the edge to his orgasm.

Closing his eyes against the onslaught, he came over Severus’ hand and shirt before his body went lax, and then rested his head on Severus’ shoulder.

Severus was gasping; his hand clenched and unclenched rhythmically around Harry’s over-sensitive cock, but Harry didn’t mind when Severus’ face was blissful. Impulsively, Harry kissed Severus’ cheek and stroked a finger along his jawline.

“Come on. You can’t sleep here,” Harry said, wincing slightly as he stood. He bent down to pick up his trousers, and then grimaced as he felt Severus’ come start to seep out of his pleasantly sore entrance.

Dark eyes flew open and with some effort, Severus wrenched himself from the chair and did up his trousers, growling, “Fine.” He made his way to the door and was halfway opening it when Harry yelped.

“What? Where are you going?”

“You just said I can’t sleep here. Where do you think I’m going? Back to my dorm.”

Harry dropped his trousers and moved round to stand in front of his lover, shutting the door. “I meant, you can’t sleep in the chair, it’s not comfortable. I was, badly, implying that we should go to bed.” Harry kissed Severus, coaxing him with his mouth that he was sincere. As he pulled away, Harry took off his shirt and dropped it on the floor. “Are you coming then?”

Severus watched Harry turn and then he started to shed his clothes, following Harry to the bedroom, eager to start their time together after fighting so hard to get what he wanted Severus wasn’t going to let Harry go any time soon.


End file.
